Type 1 and type 2 diabetes are characterized by loss and dysfunction of beta cells. Type 2 diabetes, which is the most common form, is associated with a gradual decline in sensitivity to insulin. Type 1 diabetes is a condition in which the body's immune cells attack β cells located in pancreatic islets, reducing or eliminating the body's ability to produce insulin. Treatment for type 1 diabetes is a lifelong commitment of monitoring blood glucose, exercising, dieting, and taking insulin. In some cases, individuals with type 2 diabetes similarly require insulin therapy. However, these approaches are sometimes insufficient to control blood glucose levels. Poorly controlled diabetes can lead to potentially fatal complications. Eyes, nerves and kidneys are particularly susceptible to the damage caused by poorly controlled type 1 or type 2 diabetes.
Recently great strides have been made in developing human islet transplantation in the treatment of diabetes. The lack of suitable donor pancreases is a major obstacle in the widespread use of islet cell transplants. Furthermore, this strategy faces limitations due to the large number of islets required to achieve long-term insulin independence. Often, two or far more donor organs are needed to accumulate enough islet cells for a single complete transplant. The islets are often severely injured from storage conditions or transport time causing apoptosis of the insulin secreting β-cells.